World Bird News December 2016

Volume 2 of the Illustrated Checklist of the Birds of the World

Tahiti Monarch

Volume 2 of the Illustrated Checklist of the Birds of the World goes on sale December 30th. Published by Lynx Edicions in association with HBW and BirdLife International, Volume 2 chronicles the world's passerines (perching birds), and completes the most exhaustive illustrated checklist of birds ever compiled, with stunning, full-colour portraits of all the world's 10,965 extant species. These portraits range from abundant, instantly-recognisable birds we see every day, to vanishingly rare species that will elude all but the most dedicated birder. We begin our weekly showcase of Volume 2 with a rundown of some of the rarest songbirds on our planet.Many of the world's most threatened bird species are found only on small, remote islands, where they are reliant on delicately-balanced ecosystems that are ill-equipped to deal with outside influences. This monarch flycatcher and its flute-like call is restricted to a handful of lowland valleys in Tahiti, French Polynesia, where it has been driven to near-extinction by the spread of invasive plants and rats. Intensive habitat restoration work from our French Polynesian partner Société d'Ornithologie de Polynésie (SOP MANU) has helped recover the species from just 27 birds to around 50 today, but it remains one of the world's rarest birds.

Black-winged Myna

This Indonesian endemic was previously known as the Black-winged Starling, until a closer look revealed that what we once thought was the Black-winged Starling was actually three different species: Grey-rumped Myna Acridotheres tertius (from Bali), Grey-backed Myna Acridotheres tricolor (South-east Java) and Black-winged Myna (Java, pictured). Sadly, all three of these birds are victims of the Indonesian people's love of keeping songbirds in cages; unsustainable trapping to meet demand for local trade means all three of these species are Critically Endangered, meaning they could disappear within our lifetimes.

Tragically, the Black-winged Myna was common not so long ago. However, collectors began coveting the species as a replacement for the similar looking, and extremely rare, Bali Myna Leucopsar rothschildi. The two species now have more than just looks in common.

Taita Apalis

Occupying a tiny range of just 1.5 square kilometres of fragmented forest in Kenya, this warbler has endured a population crash in recent years, with illegal logging further fragmenting its preferred montane forest habitat. Today, maybe fewer than 100 remain. BirdLife's Preventing Extinctions Programme, alongside our local Partner Nature Kenya, is now working to safeguard the remaining forest, and tree nurseries are being established in an attempt to reconnect the various scattered populations.

Regent Honeyeater

This striking honeyeater (a family of nectar-feeding birds similar to, but unrelated to, sunbirds) is a gregarious, nomadic bird that loves to travel around south-east Australia in flocks. But in recent years its breeding range has become as patchy as the canary-yellow scales on its breast. Habitat loss coming as a result of agricultural and residential development has hit the Regent Honeycreeper hard, and the few hundred birds that remain are now forced to compete with other sweet-toothed species for limited nectar resources.

Cerulean Paradise-flycatcher

Despite its vivid blue plumage, this ultra-elusive species, known only from the Indonesian island of Sangihe, evaded human eyes for over 120 years and was considered extinct, until a small population was discovered in 1998. Today, we know of fewer than 50 individuals. There is now a small bird tourism industry on the island, and the hope is this will incentivise locals to conserve what little montane forest remains on the island.

Liben Lark

This grassland specialist is known in tiny numbers from remnant habitat patches in Ethiopia, and also formerly in Somalia. There are now fewer than 250 birds left, which is even worse than it sounds, because the species has a skewed sex ratio, so the effective population size is even smaller. Community-managed grassland conservation is aiming to halt declines that are predicted to reach 80% over the next three generations. And if it doesn't? Then the Liben Lark will get the dubious honour of becoming mainland Africa's first bird extinction.

Bugun Liocichla

First spotted in 1995, and formally described as recently as 2006, this spectacular-looking babbler was the first new bird species to be discovered in India in over 50 years, and it is still only known from a tiny, mountainous area in the hills of the Eaglenest Wildlife Sanctuary in the state of Arunachal Pradesh. Named after the Bugun, the natives who live nearby, this species is staggeringly rare - perhaps as few as 14 individuals, and only three breeding pairs are known.

White-bellied Cinclodes

Fewer than 250 of this bulky ovenbird remain in bog habitat at 4,400-5000m in the High Andes of Peru, where it faces a veritable bombardment of threats: overgrazing of habitat by alpacas, llamas and sheep, removal of peat for horticulture, mining and water extraction for irrigation. A bird with very specific and fussy requirements, the outlook is bleak unless conservation efforts increase.

Europe's most threatened songbird rebounds

Think invasive species and images of chick-munching cats and rats immediately spring to mind. But many local extinctions have their roots in alien invaders of another kind: plants.

The introduction of alien plants, many of which are adapted to survive in far less welcoming climes, can be devastating to finely balanced ecosystems. Rugged species such as the Giant Hogweed Heracleum mantegazzianum, for example, have evolved the ability to develop thousands of seeds to compensate for the poor soil quality in its natural range in the Caucasus Mountains. Its introduction into gardens throughout Europe and North America, and subsequent spread into the wild, has had terrible consequences for the local fauna and flora. Evolution has given this hulking species the means to spread aggressively, and it outcompetes native plants by shading them from the sun. This has a knock-on effect for the areas native wildlife, which have adapted their needs around these now vanquished plants.

As is to be expected, the effects of invasive plants are often most acutely felt on remote islands, where species are forced to specialise their diet and behaviour around limited resources. Such is the plight that nearly starved the Azores Bullfinch Pyrrhula murina to extinction. A small, plump bird similar in looks to the female Eurasian Bullfinch Pyrrhula pyrrhula (however in the Azorean species, there is no colour difference between the two sexes), the Azores Bullfinch is endemic to São Miguel, an island that forms part of the Azores archipelago; an autonomous region of Portugal located some 1,360 km from the mainland. By all accounts, it was once a common sight on the island and was considered a pest of fruit orchards. Yet today, the species finds itself confined to a few square kilometres of fragmented laurel forest in the island's mountainous east.Both hunting and forest clearance have taken their toll on the species, but the main driver for its dramatic population collapse throughout the twentieth century has been the spread of exotic plants. Plants were introduced into the Azores archipelago for various purposes - mainly ornamental and agricultural, says Azucena de la Cruz, LIFE Terras do Priolo Project Assistant at SPEA (BirdLife in Portugal). Some of those species became invasive and presently cover large areas of the island. Today, more than 60% of the vascular flora of the Azores is considered exotic.This rude encroachment is a problem for the Azores Bullfinch in particular because, in order to combat year-round food shortages, the species has developed very specialised feeding habits that change throughout the seasons to adapt to what food is available. In spring, it feeds on flower buds; in summer, herb seeds; in autumn, it turns its attention to fruits; and, during winter, it is reliant on fern spores. The only thing that doesnt change, is that the Azores Bullfinchs various food sources consist of plant species endemic to the archipelago; these include the Azorean holly Ilex azorica, Hawkbit Leontodon rigens and the nearly extinct Azorean plum Prunus azorica.

Thus in order to survive, the Azores Bullfinch is reliant on Azorean laurel forest habitat which can boast a rich tapestry of these endemic species. However, in the last 100 years, these habitats have come under attack from exotic invaders that have escaped from gardens and naturalised. One such species, the Kahili ginger Hedychian gardneranum of India and Nepal, is recognised by the IUCN Invasive Species Specialist Group as one of the worlds worst 100 invasives. It is able to quickly colonise large areas of land by forming dense blankets of foliage that crowd out native seedlings. Today, only around two percent of the islands native laurel forest remains. This loss of local biodiversity nearly spelled the end for the Azores Bullfinch; before SPEA began work to protect and restore the species habitats, there were perhaps less than 300 pairs remaining, making it Europes rarest passerine.

Since the turn of the century, SPEA has coordinated three EU funded projects aimed at saving the Azores Bullfinchs remaining strongholds in the east. The first two projects, which took place between 2003-2008 and again between 2008-2013, were geared towards maintaining and restoring pockets of the species habitats, by means of clearing invasive plants, establishing fruit tree orchards, and planting native species in core areas and the buffer zones around them. SPEA also strove to raise awareness among Azoreans of the bird's plight, all of which helped the São Miguel Natural Park to be classified in July 2008, which now protects a significant part of the species habitat.

So far, these projects have succeeded in allowing the recovery of over 300 hectares of laurel forest and peatland habitat; bullfinch numbers have bounced back accordingly. In 2010, the population recoveries were such that the species was downlisted from Critically Endangered to Endangered, a major milestone in saving a bird that was once seemingly on an inexorable march towards extinction.The third and current project, LIFE Terras do Priolo (meaning Land of the Azores Bullfinch in Portuguese) , is working to build on the promise of these established patches of habitat by beginning work to join them together into one large contiguous area. The problem with these patches is that invasive plants, which are dominant outside of them, are able to re-enter the area and this obliges continuous maintenance of the areas, says de la Cruz. For this reason, the building of larger continuous areas was considered necessary in order to reduce the re-entering of invasive plants.

Joining up the restored patches of vegetation will not be a simple process, however; it involves revisiting areas previously considered not cost-effective to restore. The Tronqueira Mountains have very steep slopes with loose volcanic soils and several water lines that are mostly not permanent and torrential, says de la Cruz. In previous projects, we selected areas with more gentle slopes and this resulted in a series of restored patches scattered in the mountains.

The present Terras do Priolo project is also working to construct a ring around the mountain ridges to stem the further spread of the invasive plant species that have brought the Azores Bullfinch to the brink. Whether or not this ring will be effective depends on how well the interior areas can be controlled; this will involve a great deal of intensive conservation effort in the decades to come. So, although the Azores Bullfinch population continues to grow, and is edging towards the symbolic 1,000 mark, we should not become complacent; birds such as this, with such particular needs and such tiny ranges, will likely always be at risk of slipping back towards extinction, and it is essential the good work made possible by the EU's LIFE programme is allowed to continue.

Nevertheless, with the 2016 Red List delivering news that the Azores' beloved 'priolo' has now met the criteria to be eligable for a second downlisting in under a decade - this time to Vulnerable - for now we have every reason to feel bullish about the Azores Bullfinchs future.

The Cryptic Treehunter : Does it still exist ?

The Cryptic Treehunter is so elusive, researchers are not even sure it still exists anymore. The name reflects its enigmatic nature, but the reasons why its habitat is vanishing are somewhat more glaring.Juan and Dante once again ventured into the dense forests of Murici in north-eastern Brazil, hoping to see some rare birds. When the two researchers left the Centre for Ornithological Studies in São Paulo that week, they could not imagine what they were about to witness.As the two friends discussed their sightings, a flash of cinnamon brown stopped them on their tracks. Hidden in the 20m high forest canopy, there it was. A small bird that looked like an Alagoas Foliage-gleaner Philydor novaesi  itself also on the brink of extinction.But something was off. It was slightly larger and darker. The bill seemed longer. And the weirdest part: it screeched, loudly. The call could not belong to the whistling Foliage-gleaner. In fact, it sounded more like a Pale-browed Treehunter Cichlocolaptes leucophrus. But they were outside of this species range  its found in south-eastern Brazil, not in the north. What could they be looking at?

On that day in October 2002, Juan Mazar Barnett and Dante Buzzetti had in fact discovered a new species. Since it was so difficult to spot, researchers decided to call it Cryptic Treehunter. In Portuguese, it was named gritador-do-nordeste  the screamer of the northeast, after its unique screeching sound.The scientific name came a few years later, after Juan Barnett had passed away. Dante dedicated the name Cichlocolaptes mazarbarnetti to his colleague, in recognition of a life devoted to ornithology.In the following years, other researchers had the same luck as Juan and Dante and recorded new sightings of the Cryptic, until 2007, when the screamer suddenly fell silent. Almost ten years have passed and the bird has not been seen again; it was last spotted at Serra do Urubu in February 2005 and at Murici in April 2007.Since it hasnt been reported in any other sites, if the species survives, the estimated global population would be very low  under 50 individuals. As the description of the new species was confirmed, it was added to this years Red List.While researchers should be cheering for the discovery of a new species, the immediate response was concern; deforestation has been running wildwithin the home range of this small bird. This is why like other unique species in the same area, it has gone straight into the highest threat category: Critically Endangered (Possibly Extinct).Researchers have had difficulty locating the species as only the call can be used to confirm its presence. All we know is that the regions of Serra do Urubu and Murici are part of a highly threatened ecosystem and biodiversity hotspot known as the Atlantic Forest.This forest stretches across eastern Brazil, eastern Paraguay and north-eastern Argentina. It is a neotropical, humid ecosystem that is home to about 20,000 species of plants, 260 species of mammals and 700 species of birds, many of which cant be found anywhere else in the world.But the Atlantic Forest is not what it used to be. This vast region used to extend beyond 150 million hectares; an endless expanse of trees, hosting an incredible amount of endemic species, teeming with life. However, in recent years, unremitting logging and deforestation have left just 11% of it still standing.Sugarcane plantations and cattle ranching have sliced up and degraded this primeval forest. Today, the Atlantic Forest is not the continuous jungle one would imagine. The region is a mosaic of over 245,000 pieces with little original forest cover left.Most fragmentsare smaller than ten hectares and few are larger than 1,000. Theres little chance for fragments to connect with each other, as they are surrounded by sugarcane plantations: hardly a welcoming ecosystem for wild animals. The remaining patches are threatened by fire, logging and firewood removal.It does not come as a surprise that many of the inhabitants of the Atlantic Forest are in peril. In fact, over 70% of nearly 200 endemic bird species found there are of elevated conservation concern. Along the Atlantic Forest range the situation is not homogenous.In the south-east there are still some large protected areas with more than 100,000 hectares. The most extreme situation in terms of threat and fragmentation is taking place in the north-east, where both the Cryptic Treehunter and the Alagoas Foliage-gleaner live. The forest cover is declining fast and extensive logging has been reported in the areas where these birds have been sighted.However, SAVE Brasil (BirdLife Partner) is working hard to save this vital ecosystem. In 2004, they purchased one important forest area of 360 hectares, adjacent to a private reserve in Frei Caneca, Serra do Urubu. The combined area, part of which was being deforested as a result of charcoal exploitation, is today 1,000 hectares of well managed, protected forest.A year later, they started conducting bird monitoring in both reserves and while there were no records of the Treehunter or Foliage-gleaner, they have been spotting other birds such as the White-collared Kite Leptodon forbesi (Critically Endangered) and Alagoas Tyrannulet Phylloscartes ceciliae (Endangered).As the forest slowly recovers, SAVE Brasil are even recording species that havent been seen for years like the White-winged Cotinga Xipholena atropurpurea (Endangered).In the last remnants of the north-east Atlantic Forest, we might be too late to save the Alagoas Foliage-gleaner and the Cryptic Treehunter, but we still have time to try, and are working hard to save the other globally threatened birds that still survive, said Pedro Develey, Executive Director of SAVE Brasil.The Atlantic Forest and specific sites such as Murici and Serra do Urubu are the maximum priority for SAVE Brasil because so many species depend on this ecosystem. The presence of yet another new species should be a renewed reason for governments to take immediate action for their preservation.For the Cryptic Treehunter, we can only aim to conserve its habitat and continue surveying the area in the hope that the species is still extant. In the meantime, we cant help but wonder: what other species are we losing before they can even be discovered?